Explanatory notes (For details, see the technical notes).

RSEI score: Estimated population chronic health human health risk from air releases and incineration transfers reported to the US Environmental Protection Agency's Toxics Release Inventory (TRI) for the 2014 Reporting Year, as computed by the US EPA's Risk-Screening Environmental Indicators (RSEI ver. 2.3.4) from quantity released, toxicity of chemicals, and population exposure. Data are adjusted by the Corporate Toxics Information Project (CTIP) for subsequent revisions to TRI data, including where available revisions to the share of hexavalent chromium in chromium releases.Source: US EPA and Corporate Toxics Information Project (CTIP).

Quantity of toxic air releases and incineration transfers: Millions of pounds of toxic chemicals released to the air on-site or transferred offsite for incineration in the TRI 2014 Reporting Year, without adjustment for toxicity or population exposure. Source: US EPA.

Environmental Justice (EJ): Poor Share and Minority Share: Shares of the total population health risk borne by people living below the poverty line or by people in minority racial/ethnic groups. In the U.S. population, 14.5 percent live below the poverty line and 36 percent are members of minority racial/ethnic groups. Sources: US EPA, US Census, and CTIP.

Coverage: This table presents the highest toxic-score companies that appear on the Forbes Global 2000 list, 2016 ranking (first 500 companies only), the Forbes America’s Largest Private Companies list, 2016 ranking, the Fortune 500 list as of the end of 2015 (first 500 companies only), the Fortune Global 500 (made with data from fiscal years ending by March 2016), or the S&P 500 as of July 1 2016. Individual facilities are assigned to corporate parents on the basis of the most current information on their ownership structure as of late 2016. Source: CTIP.